JP5895615B2 - Sensor module, force detection device and robot - Google Patents

Description

  The present invention relates to a sensor module capable of detecting a force component, a force detection device using the same, and a robot.

  Conventionally, the thing of patent documents 1 was known as a force sensor (sensor device) using a piezoelectric material. Patent Document 1 discloses a force sensor in which a signal electrode is sandwiched between crystal disks, which are piezoelectric materials, and a measurement element sandwiched between metal cover disks is sealed in a metal ring by welding.

Japanese Unexamined Patent Publication No. Hei 4-231827

  The force sensor disclosed in Patent Document 1 may cause individual dimensional errors of the signal electrode, crystal disk, and metal cover disk. A gap is generated when welding is performed due to these errors, and moisture, outside air, or the like is generated in the gap. As a result, the charge generated in the crystal disk leaks to the outside, and there is a possibility that accurate measurement cannot be performed. Furthermore, the welding process is complicated and difficult to apply to mass production.

  Therefore, by using a sensor device as shown in FIG. 12, it is possible to obtain a sensor element that prevents leakage and does not depend on the measurement environment.

  As shown in FIG. 12, the sensor device 200 includes a sensor element 214 that sandwiches the electrode plate 218 with two crystal plates 216 having the same cut surface facing each other, and a metal device that houses the sensor element 214. The first member 202 and the metal second member 204 that is bonded to the upper surface 224 that is the outer periphery of the opening 220 of the first member 202 and that abuts against the crystal plate 216 constitute the whole. A coaxial connector 206 is attached to the side surface of the first member 202. The coaxial connector 206 has an outer peripheral portion 208 and a center conductor 210, and an insulating resin 212 is filled between them, so that the outer peripheral portion 208 and the central conductor 210 are electrically insulated. The outer peripheral portion 208 is short-circuited with the first member 202 and the second member 204, and the central conductor 210 is electrically connected to the electrode plate 218.

  The sensor device 200 is sandwiched between pressurization plates (not shown) and given pressurization, and the crystal plate 216 outputs (induces) electric charges to the electrode plate 218 due to the piezoelectric effect accompanying the pressurization. Then, the pressure applied to the crystal plate 216 changes according to the external force applied to the pressurizing plate. Therefore, the external force applied to the sensor device 200 can be detected by monitoring the change amount of the output charge due to the change in pressure through the coaxial connector 206.

  Here, in the sensor device 200, the second member 202 is filled with dry air or kept in a vacuum state so that the charge induced from the crystal plate 216 does not leak to the outside due to moisture or the like. The sensor element 214 is sealed by the member 204.

  However, when the sensor element 214 is accommodated in the first member 202, there are the following problems. In the manufacturing process of the first member 202 and the sensor element 214, the first member 202 and the second member 204 have a dimensional error, and the sensor element 214 similarly has a dimensional error. Therefore, the internal height of the first member 202 (the height from the contact surface between the first member 202 and the sensor element 214 to the contact surface at which the first member 202 and the second member 204 are joined) and the height of the sensor element 214. It was difficult to adjust the thickness equally.

  Thus, in the sensor device 200, a gap is generated between the sensor element 214 and the second member 204 due to the dimensional error, or the sensor element 214 protrudes from the upper surface 224 of the first member 202, and the second member 204 is the sensor. The element 214 is pressed. In each state, it is difficult to apply the same pressure to the sensor element 214 with the pressure plate.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A sensor module according to this application example is joined to a sensor element in which a piezoelectric body and an electrode are laminated, a first member having a first recess in which the sensor element is disposed, and the first member. A second member that seals the first recess of the first member, a first plate that contacts the second member, a second plate that contacts the first member, the first plate, and the first plate A fastening portion capable of fastening two plates, and a dimension from a contact surface between the first member and the sensor element to a surface where the first member and the second member are joined is the piezoelectric of the sensor element. The first plate is provided with a first protrusion that protrudes toward the second member and contacts the second member, and the sensor element includes: In contact with the second member And wherein the door.

  According to this application example, the sensor device in which the sensor element is sealed in the first member is pressed by the first convex portion from the outside of the second member, and the second member is deformed to be converted into the sensor element. Pressure can be applied. For this reason, a constant pressurization can always be applied to the sensor element irrespective of manufacturing variations caused by the dimensional error of the sensor device, and accurate detection data without a measurement error can be obtained.

  Application Example 2 In the sensor module according to the application example described above, it is preferable that the second plate is provided with a second convex portion that protrudes toward the first member and contacts the first member.

  According to the said structure, a clearance gap is formed in the bottom face of a 1st member, A connection wiring can be pulled out from an external terminal using the clearance gap. Further, it is possible to efficiently apply pressure from the upper and lower surfaces of the sensor element. Furthermore, a gap between the first plate and the second plate can be widened, and a space for installing wiring, a control circuit (IC) and the like can be secured.

  Application Example 3 In the sensor module according to Application Example 2, it is preferable that a second recess that fits with the second protrusion is formed on the bottom surface of the first member.

  According to the said structure, it can position by the 2nd recessed part of a 1st member, and the 2nd convex part of a 2nd plate fitting, and can align a sensor device and a 2nd plate easily.

  Application Example 4 In the sensor module according to the application example described above, in the plan view in the thickness direction of the second member, the first member has a first peripheral portion surrounding the portion that contacts the first protrusion. It is preferable to have a thin part thinner than the thickness of the part which contacts a convex part.

  According to the said structure, it has a thin part which is easy to deform | transform into the 2nd member. When a pressure is applied to the sensor device by the first convex portion, the thin portion of the second member is deformed, so that the stress is relaxed, and the bonded state of the first member and the second member can be maintained. Further, when a force in each axial direction is applied, the thin portion is deformed, whereby the force can be efficiently transmitted to the sensor element.

  Application Example 5 In the sensor module according to the application example described above, when the stacking direction of the sensor elements in which a plurality of the piezoelectric bodies are stacked is the Z-axis direction, the directions orthogonal to the Z-axis direction and to each other are respectively When the X-axis direction and the Y-axis direction are used, the first sensor element that detects at least the force in the X-axis direction, the second sensor element that detects the force in the Y-axis direction, and the force in the Z-axis direction are detected. And a third sensor element.

  Application Example 6 In the sensor module according to the application example described above, it is preferable that the fastening portion can adjust the fastening force.

  According to the above configuration, a required amount of fastening force can be applied according to the application, and stable sensor characteristics can be obtained.

  Even if it is a sensor device which detects the force of a triaxial direction by controlling the mutual position shift of the sensor element which detects the force of X direction, Y direction, Z direction, and what is called a triaxial direction by the above-mentioned composition. It can be stably maintained without impairing high detection accuracy.

  Application Example 7 A force detection device according to this application example includes a sensor element in which a piezoelectric body and an electrode are laminated, a first member having a first recess in which the sensor element is disposed, and the first member. A second member that is bonded and seals the first recess of the first member; a first plate that contacts the second member; a second plate that contacts the first member; the first plate; A fastening portion capable of fastening the second plate; and an electronic circuit electrically connected to the sensor element, wherein the first member and the second member are formed from a contact surface between the first member and the sensor element. The dimension to the surface to be joined is formed larger than the dimension in the direction in which the piezoelectric body and the electrode of the sensor element are laminated, and the first plate protrudes toward the second member and the second member The first convex part to be contacted is provided, and the front The sensor element is characterized in that in contact with the second member.

  According to the above configuration, the external force can be easily processed by the amount of charge obtained from the sensor element and the sign of the charge. In addition, a triaxial force detection sensor can be obtained with a simple configuration. Furthermore, by arranging a plurality of the sensor modules, a six-axis force detection sensor including a force in the torque direction can be obtained.

  Application Example 8 A robot according to this application example is a robot including a main body portion, an arm portion connected to the main body portion, and a hand portion connected to the arm portion, and the arm portion and the hand A sensor module in a connection part with the sensor, wherein the sensor module includes a sensor element in which a piezoelectric body and an electrode are laminated, a first member having a first recess in which the sensor element is disposed, and the first member A second member that is joined to the member and seals the first recess of the first member; a first plate that contacts the second member; a second plate that contacts the first member; and the first plate And a fastening portion capable of fastening the second plate, and a dimension from a contact surface between the first member and the sensor element to a surface where the first member and the second member are joined is the sensor element. The piezoelectric body of The first plate is formed larger than the dimension in the direction in which the electrodes are stacked, and the first plate is provided with a first protrusion that protrudes toward the second member and contacts the second member. It is in contact with two members.

  By using the above configuration, the robot arm or robot hand detects the contact with the obstacle that occurs during the specified operation, and the force detection device reliably detects the contact force with the object. By feeding back data to the device, safe and detailed work can be performed.

Sectional drawing which shows the structure of the sensor module which concerns on 1st Embodiment. The top view which shows the structure of the sensor device (a 2nd member is abbreviate | omitted) of 1st Embodiment. The top view of the base member of 1st Embodiment. The top view of the 2nd member of 1st Embodiment. The schematic diagram which shows the structure of the sensor element of 1st Embodiment. Explanatory drawing of the state which welded the 1st member and the 2nd member and accommodated the sensor element. Sectional drawing of the sensor module which concerns on 2nd Embodiment. Sectional drawing of the sensor module which concerns on 3rd Embodiment. Sectional drawing of the sensor module which concerns on 4th Embodiment. The force detection apparatus of 5th Embodiment is shown, (a) is a schematic diagram, (b) is a top view. The schematic diagram of the robot carrying the force detection apparatus of 6th Embodiment. The schematic diagram of the sensor device of a prior art.

(First embodiment)
The sensor module of this embodiment will be described in detail with reference to the drawings.
FIG. 1 is a sectional view of a sensor module according to the first embodiment. FIG. 2 is a plan view of the sensor device (the second member is omitted) of the present embodiment. FIG. 3 is a plan view of the base member of this embodiment.

<Configuration of sensor module>
The sensor module 10 according to the first embodiment includes a sensor device 11 in which a sensor element capable of detecting a force component is enclosed in a first member 12, a first plate 70 that supports the sensor device 11 so as to be sandwiched between the plates, and The main basic configuration is the second plate 80 and the fastening portion 86 that fixes the sensor device 11 between the first plate 70 and the second plate 80 while applying pressure. The sensor device 11 of the present embodiment has a first member 12, a second member 34, and a sensor element 42 as the main basic configuration.

  As shown in FIGS. 1 and 2, the first member 12 includes a base member 14 and a side wall member 24, both of which are formed of an insulating material such as ceramic. The base member 14 is a flat plate having a rectangular shape in plan view, and the sensor element 42 is disposed on the upper surface. The side wall member 24 is disposed on the base member 14 so as to surround the sensor element 42 (ring shape).

[Configuration of base member]
As shown in FIG. 3, the ground electrode 16 connected to the lower surface of the sensor element 42 is disposed at the center of the upper surface of the base member 14. In addition, external electrodes 20A, 20B, 20C, and 20D are arranged at the four corners of the lower surface of the base member 14. As shown in FIG. 1, the external electrodes 20 </ b> A, 20 </ b> B, 20 </ b> C, and 20 </ b> D are each connected to a mounting electrode 96 on the electronic circuit board 94.

  As shown in FIGS. 1, 2, and 3, connection electrodes 18 </ b> A, 18 </ b> B, 18 </ b> C, and 18 </ b> D are disposed on the upper surface of the base member 14. The connection electrodes 18A, 18B, 18C, and 18D are arranged corresponding to the external electrodes 20A, 20B, 20C, and 20D, respectively, and one ends thereof are arranged at positions facing the external electrodes 20A, 20B, 20C, and 20D in plan view. ing. One end of each of the connection electrodes 18A, 18B, 18C, and 18D and the external electrodes 20A, 20B, 20C, and 20D are electrically connected to each other through the through electrodes 22A, 22B, 22C, and 22D that penetrate the base member 14, respectively. ing. On the other hand, the other ends of the connection electrodes 18A, 18B, and 18C are arranged at positions near the ground electrode 16. The other end of the connection electrode 18D is connected to the ground electrode 16.

  As shown in FIG. 2, the side wall member 24 is laminated at a position on the base member 14. The side wall member 24 is disposed so as to cover the connection electrodes 18A, 18B, 18C, and 18D, but the other end side of the connection electrodes 18A, 18B, 18C, and 18D is exposed inside the side wall member 24, and the ground electrode 16 is also formed. The base member 14 is laminated in an exposed state. Further, as shown in FIG. 1, a metallized layer 26 is disposed on the upper surface of the side wall member 24, and this becomes the upper surface 32 of the first member 12. As shown in FIGS. 1 and 2, a through electrode 28 penetrating the side wall member 24 in the height direction is disposed at a position facing the connection electrode 18D of the side wall member 24, and the metallized 26, the connection electrode 18D, Are electrically connected through the through electrode 28.

  Accordingly, as shown in FIGS. 1 and 2, in the first member 12, the first concave portion 30 is formed in the first member 12 by the side wall member 24, and the first upper surface 32 of the side wall member 24 on which the metallized 26 is disposed is first. An outer peripheral surface serving as an outer periphery of the recess 30 is formed. The ground electrode 16 and the connection electrodes 18A, 18B, 18C, and 18D are formed of a metal having conductivity, and the metallized 26 can be formed of the same material as the ground electrode 16 and the like.

  Further, the thickness (height) of the side wall member 24 is set larger than the total thickness (height) of a first sensor element 46, a second sensor element 52, and a third sensor element 58, which will be described later.

[Configuration of second member]
FIG. 4 is a plan view of the sensor device as seen from the top through the first plate of the sensor module of the present embodiment. As shown in FIGS. 1 and 4, the second member 34 is formed in a substantially rectangular shape from a metal such as stainless steel or Kovar. And the position which overlaps with the side wall member 24 by planar view of the 2nd member 34 becomes a rectangular ring-shaped peripheral part 38, and the inner side of the peripheral part 38 is the force transmission part 36. FIG. The force transmission portion 36 is larger than the upper surface 44 that is a force receiving surface of the sensor element 42 described later in plan view of the second member 34 and smaller than the peripheral portion 38. Further, a recess is formed between the peripheral edge portion 38 and the force transmission portion 36 in the sectional view of the second member 34. The second member 34 of the present embodiment can be formed by press molding or etching. The force transmission unit 36 is in surface contact with the entire upper surface 44 serving as a force receiving surface of the sensor element 42 in a state where pressure is applied by a first plate 70 described later.

  As shown in FIG. 1, the peripheral portion 38 is joined to the metallized layer 26 that forms the upper surface 32 of the side wall member 24 by seam welding. The seam welding is performed in a dry atmosphere or a vacuum atmosphere, and the sensor element 42 is hermetically sealed in the first member 12 by seam welding between the second member 34 and the metallized 26. Here, the second member 34 is electrically connected to the connection electrode 18 </ b> D via the metallization 26 and the through electrode 28.

[Configuration of sensor element]
As shown in FIG. 1, the sensor element 42 is formed of, for example, quartz, lead zirconate titanate (PZT: Pb (Zr, Ti) O ₃ ), lithium niobate, lithium tantalate, or the like having piezoelectricity. It has a plate-like substrate, and in this embodiment, a quartz plate is used as the piezoelectric body. The sensor element 42 is formed by laminating a first sensor element 46, a third sensor element 58, and a second sensor element 52 in order from the top. The first sensor element 46 is formed such that the first quartz plates 48A and 48B sandwich the first detection electrode 50. The second sensor element 52 is formed such that the second crystal plates 54 </ b> A and 54 </ b> B sandwich the second detection electrode 56. The third sensor element 58 is formed so that the third crystal plates 60 </ b> A and 60 </ b> B sandwich the third detection electrode 62.

  A first ground electrode 64 serving as an electrode is disposed between the first sensor element 46 (first crystal plate 48B) and the third sensor element 58 (third crystal plate 60A), and the third sensor element 58 ( A second ground electrode 66 is disposed between the third crystal plate 60B) and the second sensor element 52 (second crystal plate 54A). Furthermore, the upper surface of the first sensor element 46 (first crystal plate 48A) is the upper surface 44 of the sensor element 42, and is in surface contact with the force transmission portion 36 of the second member 34 and grounded. The lower surface of the second sensor element 52 (second crystal plate 54B) is grounded by being connected to the ground electrode 16.

  As shown in FIG. 2, the first detection electrode 50, the second detection electrode 56, the third detection electrode 62, the first ground electrode 64, and the second ground electrode 66 are formed from stacked first to third crystal plates. Each part is arranged so that it protrudes. The first detection electrode 50 is connected to the exposed portion (the other end side) of the connection electrode 18A by the conductive wire 68A, and the second detection electrode 56 is connected to the exposed portion (the other end side) of the connection electrode 18B by the wire 68B. The third detection electrode 62 is connected to the exposed portion (the other end side) of the connection electrode 18C by a wire 68C. The first ground electrode 64 and the second ground electrode 66 are connected to the exposed portion (the other end side) of the connection electrode 18D by wires 68D and 68E, respectively.

  With the above connection, the external electrode 20A is electrically connected to the first detection electrode 50 through the through electrode 22A, the connection electrode 18A, and the wire 68A. The external electrode 20B is electrically connected to the second detection electrode 56 through the through electrode 22B, the connection electrode 18B, and the wire 68B. The external electrode 20C is electrically connected to the third detection electrode 62 through the through electrode 22C, the connection electrode 18C, and the wire 68C.

  The external electrode 20D is electrically connected to the ground electrode 16 through the through electrode 22D and the connection electrode 18D. Further, the external electrode 20D is electrically connected to the first ground electrode 64 via a wire 68D connected to the connection electrode 18D, and is electrically connected to the second ground electrode 66 via a wire 68E connected to the connection electrode 18D. Then, it is electrically connected to the second member 34 through the through electrode 28 and the metallized 26 connected to the connection electrode 18D.

  As the materials for the various electrodes described above, a simple substance or an alloy such as gold, titanium, aluminum, copper, or iron can be used. For example, stainless steel can be used as the iron alloy, and it is preferably used because of its excellent durability and corrosion resistance.

  FIG. 5 shows a schematic diagram of the sensor element of the present embodiment. In the present embodiment, the force transmission unit 36 is orthogonal to not only the force in the direction parallel to the normal direction (γ axis) of the upper surface 44 of the sensor element 42 but also the force in the surface direction of the upper surface 44, that is, the γ axis. In addition, forces in two directions (α axis and β axis) orthogonal to each other can be transmitted to the upper surface 44. The sensor element 42 can detect forces parallel to the α-axis, β-axis, and γ-axis, as will be described later.

  In the first sensor element 46, the first crystal plates 48A and 48B are formed of Y-cut crystal plates, and the X direction, which is the crystal orientation for generating the piezoelectric effect, is normal to the first crystal plates 48A and 48B (FIG. 5). The crystal orientation is perpendicular to the direction parallel to the γ-axis. The first crystal plates 48A and 48B are arranged so that the X directions are opposite to each other. Furthermore, the first crystal plates 48A and 48B are arranged so that the X direction is parallel to the α axis of the space orthogonal coordinates.

  In the second sensor element 52, the second crystal plates 54A and 54B are formed of Y-cut crystal plates, and the X direction is perpendicular to the normal line (the direction parallel to the γ axis) of the second crystal plates 54A and 54B. The crystal orientation is as follows. The second crystal plates 54A and 54B are arranged so that the X directions are opposite to each other. Further, the second crystal plates 54A and 54B are arranged so that the X direction is parallel to the β-axis of the space orthogonal coordinates.

  In the third sensor element 58, the third crystal plates 60A and 60B are formed by X-cut crystal plates, and the X direction is parallel to the normal line (the direction parallel to the γ axis) of the third crystal plates 60A and 60B. The crystal orientation is as follows. The third crystal plates 60A and 60B are arranged so that the X directions are opposite to each other. Furthermore, the third crystal plates 60A and 60B are arranged so that the X direction is parallel to the γ-axis of the space orthogonal coordinates.

  As shown in FIG. 5, the sensor element 42 of the present embodiment has a direction parallel to the γ-axis of the space orthogonal coordinates as the height direction of the sensor element 42. Then, the first plate 70 and the second plate 80, which will be described later, are sandwiched from the direction of the γ-axis and given pressure, and the pressure is applied to the sensor element 42 through the first convex portion 72 from the direction parallel to the γ-axis. Is done. As a result, the third crystal plates 60A and 60B receive pressure (compression force) from the X direction, so that charge is induced by the piezoelectric effect, and charge (Fz signal) is output to the third detection electrode 62.

  In the above-described configuration, when an external force is applied in which the relative positions of the first plate 70 and the second plate 80 (see FIG. 10) are shifted in the direction parallel to the α axis, the sensor element 42 is interposed via the first convex portion 72. Is applied with an external force in a direction parallel to the α-axis. Then, since the first quartz plates 48A and 48B receive external force (shearing force) from the X direction, charges are induced by the piezoelectric effect, and charges (Fx signal) are output to the first detection electrode 50.

  Further, when an external force is applied in which the relative positions of the first plate 70 and the second plate 80 (see FIG. 10) are shifted from each other in the direction parallel to the β axis, the sensor element 42 is connected to the sensor element 42 via the first protrusion 72. An external force in a direction parallel to the axis is applied. Then, since the second crystal plates 54A and 54B receive external force (shearing force) from the X direction, electric charges are induced by the piezoelectric effect, and electric charges (Fy signals) are output to the second detection electrodes 56.

  Further, when an external force is applied so that the relative positions of the first plate 70 and the second plate 80 (see FIG. 10) are shifted in the direction parallel to the γ axis, the sensor element 42 is subjected to γ via the first protrusion 72. An external force in a direction parallel to the axis is applied. Then, since the third crystal plates 60A and 60B receive an external force (compression force or tensile force) from the X direction, the amount of charge induced by the piezoelectric effect changes, and the charge output to the third detection electrode 62 ( The magnitude of the (Fz signal) changes.

  Therefore, the sensor device 11 of the present embodiment has a charge (Fx signal) output to the first detection electrode 50 via the external electrode 20A and a charge (Fx signal) output to the second detection electrode 56 via the external electrode 20B. Fy signal) and the charge (Fz signal) output to the third detection electrode 62 via the external electrode 20C can be monitored, respectively, and an α axis (X axis described later), β axis (described later) It is possible to detect external forces (Fx, Fy, Fz) in a direction parallel to the Y axis (described later) and the γ axis (Z axis described later). The sensor element 42 has a laminated structure of the first sensor element 46, the second sensor element 52, and the third sensor element 58, but may be configured to use at least one of them.

<Method for manufacturing sensor device>
In the manufacturing method of such a sensor device 11, as shown in FIG. 6, first, the sensor element 42 is placed on the base member 14, and then the peripheral portion 38 of the second member 34 is the side wall member 24 of the first member 12. It arrange | positions so that it may correspond with the upper surface. Then, a weight is disposed in the center of the second member 34 and a load is applied to the second member 34. Then, the roller electrode is pressed against the connection position of the second member 34 with the metallization 26 (side wall member 24), and an electric current is applied to the roller electrode to join the second member 34 and the metallization 26 by seam welding.
Thus, the sensor device 11 is in a state where a gap is generated between the sensor element 42 and the second member 34.

[Configuration of the first and second plates]
The first plate 70 of the present embodiment is a substantially rectangular plate plate that is larger than the first member 12 in plan view. The first plate 70 is made of a metal material such as stainless steel, and has a predetermined strength and can be easily formed. The first plate 70 has a convex first convex portion 72 protruding toward the second member 34 on the main surface on the first member 12 side. The first convex portion 72 includes a pressing surface 73 that overlaps with the entire region of the upper surface 44 of the sensor element 42 in a plan view and fits inside the inner peripheral region of the first member 12. In other words, the area of the pressing surface 73 is equal to or larger than the area of the upper surface of the sensor element 42 and smaller than the area of the inner peripheral edge of the first member 12 (smaller than the force transmission portion 36 of the second member 34). Forming). The 1st convex part 72 can be formed by press work or an etching. The first plate 70 has a through hole 74 into which a fastening portion 86 such as a bolt described later is inserted. The through hole 74 includes a first hole 74A into which the head of the fastening portion 86 is inserted, and a second hole 74B into which the shaft is inserted.

  The second plate 80 is a plate plate that is larger than the first member 12 in plan view and has substantially the same shape as the first plate 70. The second plate 80 is formed with a screw hole 82 into which a male screw of a fastening portion 86 described later is screwed. The second plate 80 is made of a metal material such as stainless steel and has a predetermined strength and can be easily formed. An electronic circuit board 94 is formed on the upper surface of the second plate 80 and is configured to be electrically connected to the external electrodes 20A, 20B, 20C, and 20D of the sensor device 11. Note that the first plate 70 and the second plate 80 may be formed in a disk, an ellipse, or a polygon in addition to a rectangular shape in plan view.

  The fastening portion 86 is a member that fastens the first plate 70 and the second plate 80 in a state where the sensor device 11 is sandwiched between the first plate 70 and the second plate 80. The fastening part 86 of this embodiment is a fastening bolt. The fastening bolt is composed of a head and a shaft. The tip of the shaft is formed with a threaded male screw and can be screwed into the screw hole 82 of the second plate 80. Such a fastening portion 86 only needs to be able to fix the sensor device 11 between the first plate 70 and the second plate 80 while applying pressure. In this embodiment, the fastening device 86 is installed at two locations so as to sandwich the sensor device 11 as an example. doing. In this manner, the fastening force between the first plate 70 and the second plate 80 can be adjusted by the fastening portion 86. Further, the adjustment of the fastening force is to adjust the gap between the first plate 70 and the second plate 80.

[Assembly of sensor module]
In assembling such a sensor module 10, first, the sensor device 11 is placed on the electronic circuit board 94 formed on the mounting surface of the second plate 80, and the external electrodes 20 </ b> A, 20 </ b> B, 20 </ b> C, 20 </ b> D and the mounting electrode 96 are mounted. Connect electrically. Then, the first plate 70 is disposed on the sensor device 11 so that the first convex portion 72 and the upper surface of the sensor element 42 of the sensor device 11 overlap in plan view. Next, a fastening bolt to be the fastening portion 86 is inserted from the through hole 74 of the first plate 70 and screwed into the screw hole 82 of the second plate 80. At this time, the tightening amount of the fastening portion 86 can be adjusted so that a predetermined pressure (for example, about 10 kN) is applied.

〔effect〕
According to the sensor module having such a configuration, the sensor element 42 is sealed from the outside of the second member 34 via the first protrusion 72 with respect to the sensor device 11 in which the sensor element 42 is sealed in the first member 12. A predetermined pressurization can be applied.

  In this way, the sensor element 42 can be constantly applied with a constant pressure, and accurate detection data free from measurement errors can be obtained. Therefore, the yield of the sensor device 11 is improved. Furthermore, since the sensor element 42 inside the second member 34 can be protected even when used in an environment exposed to a liquid such as lubricating oil, water or chemicals, the highly reliable sensor module 10. Can be obtained.

(Second Embodiment)
FIG. 7 is a cross-sectional view of the sensor module according to the second embodiment. 10 A of sensor modules which concern on 2nd Embodiment replace with the electronic circuit board 94 of the 2nd plate 80 of 1st Embodiment, and have provided the 2nd convex part 84. FIG. The other configuration is the same as that of the sensor module 10 of the first embodiment, and the same reference numerals are given and detailed description is omitted.

  The second plate 80 </ b> A has a second protrusion 84 having substantially the same shape as the first protrusion 72 on the mounting surface on which the sensor device 11 is mounted. The second convex portion 84 includes a pressing surface 85 that is smaller than the bottom surface of the first member 12 in plan view and has an area equal to or larger than the area of the lower surface of the sensor element 42.

According to the sensor module 10A according to the second embodiment having such a configuration, the sensor element 42 of the sensor device 11 can be pressurized evenly and effectively from the upper and lower surfaces. Further, since gaps are formed between the external electrodes 20A, 20B, 20C, and 20D formed on the bottom surface of the sensor device 11 and the second plate 80A , the metal wiring can be easily pulled out, and an external electronic circuit It can be easily electrically connected to the substrate.

(Third embodiment)
FIG. 8 is a cross-sectional view of a sensor module according to the third embodiment. In the sensor module 10 </ b> B according to the third embodiment, the second concave portion 15 in which the second convex portion 84 is fitted is formed on the lower surface of the first member 12. The other configuration is the same as that of the sensor module 10A of the second embodiment, and the same reference numerals are given and detailed description is omitted.

  The second recess 15 of the present embodiment is formed on the bottom surface of the base member 14 of the first member 12 at a position facing the lower surface of the sensor element 42. The second concave portion 15 can be formed by pressing, etching, or the like so as to be a downward concave shape into which the second convex portion 84 is fitted.

  According to the sensor module 10B according to the third embodiment having such a configuration, the center of the sensor element 42 placed on the base member 14 and the center of the second convex portion 84 of the second plate 80A are the same in plan view. It can be easily positioned so as to be in a straight line. Therefore, it is possible to apply a pressure to the sensor element 42 evenly.

(Fourth embodiment)
FIG. 9 is a cross-sectional view of a sensor module according to the fourth embodiment. In the sensor module 10C of the fourth embodiment, a thin portion 40 is formed on the second member 34A. Other configurations are the same as those of the sensor module 10 of the first embodiment, and the same reference numerals are given and detailed descriptions thereof are omitted.

  The thin portion 40 is formed in a ring shape between the peripheral portion 38 of the second member 34A and the force transmitting portion 36 in plan view. The thin portion 40 is arranged so that the periphery of the upper surface 44 of the sensor element 42 is accommodated in the inner periphery thereof in plan view. The thin portion 40 is formed so that the thickness thereof is thinner than that of the force transmission portion 36 and the peripheral portion 38 in a state where the thin portion 40 is dug from only one side or both sides of the second member 34A. The thin portion 40 can be formed by press molding or etching.

In the sensor module 10 </ b> C according to the fourth embodiment having such a configuration, the second member 34 </ b> A is not stressed because the thin portion 40 of the second member 34 </ b> A is easily deformed by the pressure applied by the first protrusion 72. The connection between the first member 12 and the second member 34A is not broken, and the inside of the sensor device 11 can be kept airtight.
The thin portion 40 may be applied to the second member of the sensor module according to the second and third embodiments.

(Fifth embodiment)
FIG. 10 shows the force detection device of this embodiment, (a) shows a schematic diagram, and (b) shows a plan view. The force detection device 90 of the present embodiment has a configuration in which four sensor devices 11 are sandwiched between a first plate 70A and a second plate 80A. The first plate 70 A 及 beauty second plate 80 A are both formed in a circular plate shape in plan view, are arranged four sensor devices 11 on a line perpendicular to each other through the center. The first plate 70 </ b> A has four first protrusions 72 formed at locations facing the upper surface of the sensor element 42 of the sensor device 11. On the second plate 80A, four electronic circuit boards are formed at locations where the sensor devices 11 are arranged. On the second plate 80A, four electronic circuit boards are formed at locations where the sensor devices 11 are arranged.

  The force detection device 90 having such a configuration is sandwiched between the first plate 70A and the second plate 80A in a state where all the four sensor devices 11 face in the same direction, and pressure is applied. For example, in the sensor module 10, the detection axis of the first sensor element 46 (FIGS. 1 and 5) is oriented in a direction parallel to Fx, and the detection axis of the second sensor element 52 (FIGS. 1 and 5) is parallel to Fy. The detection axis of the third sensor element 58 (FIGS. 1 and 5) is directed in a direction parallel to Fz. Note that the height of the sensor element of each sensor module 10 is measured in advance, and the amount of protrusion of the first convex portion 72 is adjusted by polishing or the like based on this measured value, resulting in manufacturing variations of the sensor devices 11. Even in this case, it is possible to apply the pressure evenly while maintaining the parallelism between the first plate 70A and the second plate 80A.

  Here, when receiving a force in which the relative positions of the first plate 70A and the second plate 80A are shifted in the Fx direction, the sensor module 10 detects the forces of Fx1, Fx2, Fx3, and Fx4, respectively. In addition, when the relative position of the first plate 70A and the second plate 80A receives a force that shifts in the Fy direction, the sensor module 10 detects the forces of Fy1, Fy2, Fy3, and Fy4, respectively. Further, when receiving a force in which the relative positions of the first plate 70A and the second plate 80A are shifted from each other in the Fz direction, the sensor module 10 detects the forces of Fz1, Fz2, Fz3, and Fz4, respectively.

  Therefore, in the force detection device 90, the rotational force Mx is set to a direction parallel to the forces Fx, Fy, Fz, and Fx orthogonal to each other, and the rotational force My and Fz is set to be parallel to the direction parallel to Fy. The rotational force Mz whose direction is the rotation axis can be obtained as follows.

ここで、ａ、ｂは定数とする。よって本実施形態の力検出装置９０は、三次元のあらゆる方向からの力（６軸方向の力）を検知することができ、少ない変位量であっても高精度な力の検出を安定的に行うことが可能な力検出装置９０となる。

Here, a and b are constants. Therefore, the force detection device 90 according to the present embodiment can detect forces from all three dimensions (forces in six axes) and stably detect highly accurate forces even with a small amount of displacement. The force detection device 90 can be performed.

  In this embodiment, four sensors are used. However, if there are three or more sensors, the above-described Fx, Fy, Fz, Mx, My, and Mz can be detected.

(Sixth embodiment)
FIG. 11 shows a robot equipped with the force detection device of this embodiment. As shown in FIG. 11, the robot 100 includes a main body 102, an arm 104, a robot hand 116, and the like. The main body 102 is fixed on, for example, a floor, a wall, a ceiling, or a movable carriage. The arm unit 104 is provided so as to be movable with respect to the main body unit 102. The main body unit 102 has an actuator (not shown) that generates power for rotating the arm unit 104 and a control for controlling the actuator. Etc. (not shown) are incorporated.

  The arm unit 104 includes a first frame 106, a second frame 108, a third frame 110, a fourth frame 112, and a fifth frame 114. The first frame 106 is connected to the main body 102 so as to be rotatable or bendable via a rotating and bending shaft. The second frame 108 is connected to the first frame 106 and the third frame 110 via a rotating and bending shaft. The third frame 110 is connected to the second frame 108 and the fourth frame 112 via a rotating and bending shaft. The fourth frame 112 is connected to the third frame 110 and the fifth frame 114 via a rotating and bending shaft. The fifth frame 114 is connected to the fourth frame 112 via a rotating and bending shaft. The arm unit 104 is driven by each frame being rotated or bent in a compound manner around each rotation / bending axis under the control of the control unit.

  A robot hand unit 116 is attached to the tip of the fifth frame 114, and the robot hand 120 capable of grasping an object is connected via a robot hand connection unit 118 having a built-in motor (not shown) that rotates. Connected to the fifth frame 114.

  In addition to the motor, the robot hand connection unit 118 incorporates the aforementioned force detection device 90 (not shown in FIG. 11). When the robot hand unit 116 is moved to a predetermined operation position by the control of the control unit. , Contact with an obstacle or contact with an object by an operation command beyond a predetermined position is detected as a force by the force detection device 90 and fed back to the control unit of the robot 100 to execute an avoidance operation. Can do.

  By using such a robot 100, it is possible to easily perform an obstacle avoidance operation, an object damage avoidance operation, etc., which cannot be dealt with by conventional position control, and obtain a robot 100 capable of safe and detailed work. Can do. Furthermore, the robot 100 can stably detect a highly accurate force even with a small amount of displacement. Further, the present invention is not limited to this embodiment, and can be applied to a double-arm robot.

  DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C ... Sensor module, 11 ... Sensor device, 12 ... 1st member, 14 ... Base member, 15 ... 2nd recessed part, 16 ... Ground electrode, 18A, 18B, 18C, 18D ... Connection electrode, 20A , 20B, 20C, 20D ... external electrode, 22A, 22B, 22C, 22D ... through electrode, 24 ... side wall member, 26 ... metallized, 28 ... through electrode, 30 ... first recess, 32 ... upper surface (outer peripheral surface), 34 34A ... second member 36 ... force transmission part 38 ... peripheral part 40 ... thin wall part 42 ... sensor element 44 ... upper surface 46 ... first sensor element 48A, 48B ... first crystal plate 50 ... First detection electrode 52 ... second sensor element 54A, 54B ... second crystal plate 56 ... second detection electrode 58 ... third sensor element 60A, 60B ... third crystal plate 62 ... third detection current 64 ... 1st ground electrode, 66 ... 2nd ground electrode, 68A, 68B, 68C, 68D, 68E ... Wire, 70 ... 1st plate, 72 ... 1st convex part, 73 ... Pressing surface, 74 ... Through-hole, 80, 80A ... second plate, 82 ... screw hole, 84 ... second convex part, 86 ... fastening part, 90 ... force detecting device, 94 ... electronic circuit board, 96 ... mounting electrode, 100 ... robot, 102 ... main body part , 104 ... arm part, 106 ... first frame, 108 ... second frame, 110 ... third frame, 112 ... fourth frame, 114 ... fifth frame, 116 ... robot hand part, 118 ... robot hand connection part, 120 DESCRIPTION OF SYMBOLS ... Robot hand, 200 ... Sensor device, 202 ... 1st member, 204 ... 2nd member, 206 ... Coaxial connector, 208 ... Outer peripheral part, 210 ... Center conductor, 212 ... Insulating resin, 14 ... sensor element, 216 ... Crystal plate, 218 ... electrode plate, 220 ... opening, 224 ... upper surface.

Claims (8)

A sensor element in which a piezoelectric body and an electrode are laminated;
A first member having a first recess comprising a base member and a sidewall member to which the sensor element is Ru are arranged,
A second member joined to the first member and sealing the first recess of the first member;
A first plate in contact with the second member;
A second plate in contact with the first member;
A fastening portion capable of fastening the first plate and the second plate;
The dimension from the contact surface between the first member and the sensor element to the surface where the first member and the second member are joined is larger than the dimension in the direction in which the piezoelectric body and the electrode of the sensor element are stacked. Formed large,
A sensor module, wherein the first plate is provided with a first protrusion that protrudes toward the second member and contacts the second member, and the sensor element is in contact with the second member.   The sensor module according to claim 1, wherein the second plate is provided with a second convex portion that protrudes toward the first member and contacts the first member.   The sensor module according to claim 2, wherein a second recess is formed on the bottom surface of the first member so as to be fitted with the second protrusion.   In the plan view in the thickness direction of the second member, a thin portion thinner than the thickness of the portion in contact with the first protrusion is formed in the peripheral portion surrounding the portion in contact with the first protrusion of the second member. It has, The sensor module as described in any one of Claim 1 thru | or 3 characterized by the above-mentioned.   When the stacking direction of the sensor elements in which a plurality of the piezoelectric bodies are stacked is the Z-axis direction, when the directions orthogonal to the Z-axis direction and orthogonal to each other are the X-axis direction and the Y-axis direction, respectively, at least the X A first sensor element for detecting an axial force, a second sensor element for detecting the Y-axis direction force, and a third sensor element for detecting the Z-axis direction force. The sensor module according to any one of claims 1 to 4.   The sensor module according to claim 1, wherein the fastening portion is capable of adjusting a fastening force. A sensor element in which a piezoelectric body and an electrode are laminated;
A first member having a first recess comprising a base member and a sidewall member to which the sensor element is Ru are arranged,
A second member joined to the first member and sealing the first recess of the first member;
A first plate in contact with the second member;
A second plate in contact with the first member;
A fastening portion capable of fastening the first plate and the second plate;
An electronic circuit electrically connected to the sensor element,
The dimension from the contact surface between the first member and the sensor element to the surface where the first member and the second member are joined is larger than the dimension in the direction in which the piezoelectric body and the electrode of the sensor element are stacked. Formed large,
The first plate is provided with a first convex portion that protrudes toward the second member and contacts the second member, and the sensor element is in contact with the second member. . The main body,
An arm portion connected to the main body portion;
A hand unit connected to the arm unit,
A sensor module is provided at a connection portion between the arm portion and the hand portion,
The sensor module is
A sensor element in which a piezoelectric body and an electrode are laminated;
A first member having a first recess comprising a base member and a sidewall member to which the sensor element is Ru are arranged,
A second member joined to the first member and sealing the first recess of the first member;
A first plate in contact with the second member;
A second plate in contact with the first member;
A fastening portion capable of fastening the first plate and the second plate;
The dimension from the contact surface between the first member and the sensor element to the surface where the first member and the second member are joined is larger than the dimension in the direction in which the piezoelectric body and the electrode of the sensor element are stacked. Formed large,
The robot according to claim 1, wherein the first plate is provided with a first protrusion that protrudes toward the second member and contacts the second member, and the sensor element is in contact with the second member.

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